Over the past few years, much has been written on preserving biological diversity (or biodiversity) around the world. Biodiversity is the variety of life and all its processes and includes the living organisms, their genetic differences and the communities in which they occur.
Protection of the world’s remaining rainforests, with their incredible variety of plants and animals, is the key to conserving global biodiversity. At the same time, it is also important to protect the diversity of all our natural ecosystems, whether that be wetlands, forests or shorelines. But why bother protecting biodiversity? And can we become “intelligent tinkerers,” protecting and restoring biodiversity at home? The first question is the most complex. Even highly-regarded ecologists and biodiversity experts will admit they do not know exactly how ecosystems function.
Let’s take a small stretch of the Orwell River that runs through the Sir Andrew Macphail homestead. As a forest type, it is primarily large, older hemlock, white pine, yellow birch and balsam fir. Yet the diversity that makes up this ecosystem is very rich and interacts in ways that we do not understand. It includes other trees, soil bacteria, earthworms, flowers, ferns, shrubs, insects, fish, stream invertebrates, resident and migratory birds, rodents and other small mammals, amphibians, moulds and fungi, and of course, humans. There are hundreds, if not thousands of different species interacting along the stream, and we know very little about how they work together. That they are connected, though, is very clear.
A chipmunk stores acorns from a red oak tree underground for the winter. A coyote catches the chipmunk in the open and has it for lunch one day, and the acorns are free to germinate into seedlings, which one day may grow into large trees that produce more acorns. Or take the caterpillar feeding on the leaves of speckled alders along the stream. It soon becomes a snack for a yellow-rumped warbler, which in turn might be eaten by a sharp-shinned hawk. These are all components of the “web” that makes up an ecosystem.
What happens to one species if we remove another? Species have multiple roles to play within a given ecosystem – a tree stores carbon, provides nesting sites and food for a variety of animals, and will provide a source of nutrients for a future forest. A chanterelle mushroom helps the trees around it absorb nutrients from the soil and is a source of food for red squirrels and humans. Scientists do not know what species are most important. Taking away one component of an ecosystem can have disastrous effects on the health of that community. We should protect biodiversity because we do not know what parts of the ecosystem might turn out to be important. Another reason to protect biodiversity at home is the example it sets for others. It is critical to global environmental health that countries with vast tracts of undisturbed rainforest do not continue or accelerate present harvesting rates. Forests provide humans with a wide variety of products, from foods to medicines to chemicals.
At the same time, we know that very few forest plants have been tested for what they might someday provide to humanity. The western yew growing in British Columbia forests is the source of taxol, one of the most potent anti-cancer substances ever found. There are undoubtably many more plants that have similar benefits to offer, if only we take the time to look. If wealthy countries can not conserve biodiversity, how can the world’s poorer countries ever be expected to? The tree and shrub species in most forests add a small but important part to the diversity of that community. The mixture of species and ages provides homes and food for a variety of wildlife. It also protects the forest from large scale destruction by insects and diseases, and makes excellent use of available sunlight, soil and water resources.
Protecting biodiversity in forests safeguards those ecosystems and helps maintain healthy wildlife populations. Much concern about the worldwide loss of biodiversity originally focussed on endangered species. Today, it goes beyond that, to include protection of ecosystems and restoration of degraded areas. Edward O. Wilson advises us to “go beyond mere salvage to begin the restoration of natural environments, in order to enlarge wild populations and stanch the hemorrhaging of biological wealth. There can be no purpose more enspiriting than to begin the age of restoration, reweaving the wondrous diversity of life that still surrounds us”. It is important to remember that biodiversity does not mean variety at any cost. Zoos contain an incredible diversity of wildlife, yet they do not represent biodiversity. The goal is to have healthy, fully-populated communities or ecosystems with the wide variety of inhabitants that would naturally occur in that area. Obviously this does not mean that ecosystems will remain static. They change by themselves over time, and human activities and interventions can bring both positive and negative changes. Protecting or restoring biodiversity means looking to work with nature, using native species whenever possible.
The following pages are meant to be a guide, rather than a blueprint, for using native trees and shrubs to restore biodiversity, protect watersheds, enhance habitat for wildlife and add beauty to our homes. For a variety of reasons, it is impossible to be exactly sure what plants are or are not natives. The debate is not critical. Plants migrate, their seeds spread by wind, water and animals (including people). There are plants native to New Brunswick and Nova Scotia that are not considered native in this province. Would they have naturally migrated here, spread by wind or animals? And since 80% of Prince Edward Island was cleared for farming by the late 1800’s, many small populations of trees and shrubs could have been wiped out without anyone being aware of the loss. The Plants of Prince Edward Island (updated in 1985 with new records) is the best source of information and we try to stay within their findings of native and introduced species. No effort is made to list all the native trees and shrubs, especially since some shrubs such as willow hybridize freely, but we have listed the large majority of species.
Native plants are usually very reliable they have adapted to the climatic conditions of the area and serve a variety of functions within the ecosystem. Most are proven performers hardy, fitting into a wide variety of habitats, valuable to wildlife, useful for stabilizing streambanks and/or controlling soil erosion. A good starting point to restoring biodiversity is to carefully match the plant to the site. It makes little sense to plant a sun loving tree in the shade or a shrub that will not tolerate salt spray along the shore. Use common sense and caution when planning and planting, and you won’t go too far wrong.
Biodiversity and the Role of the Macphail Wood’s Project
Biodiversity in its simplest definition, is the quanitative and qualitative complexity of flora and fauna in any given ecosystem. It is a critical component of every aspect of our natural world and changes to habitat are directly linked to changes to biodiversity. In our consumer-driven and industrial world, habitat changes have had countless effects on our natural world. In response to the state of the global envrionment, the Smithsonian Institute/Man and the Biosphere Biodiversity Program (SI/MAB), in 1987, began an extensive study of monitoring biodiversity and forest dynamics in temperate and tropical ecosystems. By increasing our knowledge of changes to these critical areas, we may implement policy to maintain, restore and protect our ecological communities for future generations.
A permanent network of research areas has been established world-wide, in such places as Bolivia, Peru, Guyana, Puerto Rico, U.S.Virgin Islands, Tennessee and here at the Macphail Wood’s homestead. These long-term monitoring projects gather data and help train scientists, students, land managers and others. An important aspect to this exciting program has been the Biological Monitoring Database (BioMon), a computer program for data collection, analysis and interpretation. BioMon allows for efficient data collection and then quickly provides a liason with users of this information. This program allows for consistent documentation of biological information gathered from plots. In the case of the Macphail Wood’s project, there are two, one hectare plots, with each plot divided into 25 quadrats of 20m X 20m. Each quadrat is accurately inventoried for species composition and this data is then placed into the BioMon program.